vkyyu:
I see your point of view regarding exams - but I've always taken the view that testing (phonics screening in Y1/ end KS1 SATs end Y2) - isn't just about telling a child they're dim and frankly I don't think most children really absorb they're even being 'tested' in Y1/ Y2. I've always seen this as an opportunity as a parent to understand how my child is progressing against national standards.
I've personally never seen DD1 doing poorly on an exam as just her failure - it was also mine as her parent and the schools. And it is a very poor school indeed who doesn't see a child failing to perform at NC2 level at end KS1 SATs as a failure.
The test is how a school handles poor results vis a vis the pupil & the parents. St. Mediocre chose to say to us that we 'just needed to understand our DD1 was a bit dim'. Apparently there was no point them trying with her.
I take the view that no child is automatically bright or dim - every child has strengths & weakness and individual ways of learning. Once we worked out that the issue was DD1 is an extremely visual learner & was the type of kid that needed to go away and do it herself (sometimes quite a few times) we were able to rectify a lot of the problem at home (things like Maths Factor totally turning around poor progress in maths).
So vkyyu I'd put it to you that as the parent it's up to you to interpret testing results:
You can send the message - I don't put a lot of store in this
You can send the message - Oh dear, that's a bit disappointing, perhaps it wasn't your day/ whilst also talking to the school about what you can do to help improve your DC's progress
you can send the message that 'effort' is as important to you as results
Getting a bad result doesn't necessarily mean your child is a failure - that's it, pack up the shop. Getting a bad result can be that chance to recognise there's a problem and start to work hard to get the help your child needs right now ....
HTH